The more intense the pressure, the brighter the light it emits, scientists said. A research team led by Ali Javey, University of California, Berkeley associate professor of electrical engineering and computer sciences created the first user-interactive sensor network on flexible plastic.

"With the interactive e-skin, we have demonstrated an elegant system on plastic that can be wrapped around different objects to enable a new form of human-machine interfacing," said Javey.

The latest e-skin builds on Javey's earlier work using semiconductor nanowire transistors layered on top of thin rubber sheets.

In addition to giving robots a finer sense of touch, the engineers believe the new e-skin technology could also be used to create things like wallpapers that double as touchscreen displays and dashboard laminates that allow drivers to adjust electronic controls with the wave of a hand.

"I could also imagine an e-skin bandage applied to an arm as a health monitor that continuously checks blood pressure and pulse rates," said study co-lead author Chuan Wang.

The experimental samples of the latest e-skin measure 16-by-16 pixels. Within each pixel sits a transistor, an organic LED and a pressure sensor, researchers said.

"Integrating sensors into a network is not new, but converting the data obtained into something interactive is the breakthrough," said Wang.

To create the pliable e-skin, the engineers cured a thin layer of polymer on top of a silicon wafer. Once the plastic hardened, they could run the material through fabrication tools already in use in the semiconductor industry to layer on the electronic components.

After the electronics were stacked, they simply peeled off the plastic from the silicon base, leaving a freestanding film with a sensor network embedded in it.